Electric pump

Abstract

An electric pump includes a motor rotor provided in a first end region in the axial direction of a rotary shaft, a pump rotor provided in a second end region in the axial direction of the rotary shaft, and a pump housing supporting the rotary shaft. The pump housing has a first housing portion for accommodating the pump rotor and a second housing portion having a blocking portion. The first housing portion has a suction port for drawing in fluid and a discharge port for discharging the drawn-in fluid.

What is claimed is: 
     
       1. An electric pump comprising:
 a rotary shaft having a first end region and a second end region in an axial direction; 
 a motor rotor located in the first axial end region of the rotary shaft; 
 a motor stator, which surrounds the motor rotor in the circumferential direction; 
 a motor case, which accommodates the motor rotor and the motor stator, the motor case having a first open end, and a second open end which is located on the opposite side to the first open end; 
 a cover member provided at the second open end of the motor case, the cover member forming an accommodating space for a circuit board, 
 a pump rotor located in the second axial end region of the rotary shaft; and 
 a pump housing, which rotationally supports the rotary shaft and holds the pump rotor, wherein 
 the pump housing includes a first housing portion and a second housing portion, the first housing portion having an accommodating recess, which opens toward the motor rotor and accommodates the pump rotor, the second housing portion having a blocking portion closing the accommodating recess, 
 the accommodating recess and the blocking portion form a pump chamber, and 
 the first housing portion has a suction port for drawing fluid into the pump chamber and a discharge port for discharging the fluid drawn into the pump chamber to the outside of the pump chamber, and is assembled to the first open end of the motor case; 
 wherein the motor case and the cover member are made of a metal material having ferromagnetic property, and the motor case makes metal-to-metal contact to the cover member and the pump housing, 
 a motor flange and a cover flange, which extend in the radial direction, are formed at the second open end of the motor case and the cover member, respectively, 
 the motor flange and the cover flange are fixed to make metal-to-metal contact with each other, 
 the electric pump further comprises a connector member having an annular portion, 
 an external connection portion extends from the annular portion of the connector member and has a connection wire for feeding electricity to the circuit board, and 
 the annular portion, the cover flange, and the motor flange are integrated, with the motor flange being axially sandwiched by the annular portion and the cover flange. 
 
     
     
       2. The electric pump according to  claim 1 , wherein the cover flange is fixed to the entire circumference of the motor flange. 
     
     
       3. The electric pump according to  claim 1 , wherein the electric pump is configured to be assembled to a power transmission device having a recessed pump accommodating portion with at least part of the motor case and the pump housing fitted in the pump accommodating portion. 
     
     
       4. The electric pump according to  claim 1 , wherein the motor stator is located between the circuit board and the pump housing. 
     
     
       5. The electric pump according to  claim 1 , wherein the distance in the axial direction between the axial center of the motor stator and the second open end is shorter than the distance in the axial direction between the axial center of the motor case and the second open end. 
     
     
       6. The electric pump according to  claim 5 , wherein part of the motor stator protrudes from the second open end of the motor case. 
     
     
       7. The electric pump according to  claim 1 , further comprising a board holder, which is made of a metal material and supports the circuit board,
 wherein the board holder is configured to make metal-to-metal contact with at least one of the motor case and the cover member. 
 
     
     
       8. The electric pump according to  claim 7 , wherein the board holder includes a heat absorbing portion, which contacts a circuit element on the circuit board.